Morphometric grading of bladder tumors in comparison with histologic grading by pathologists.

The authors describe the results of the grading of bladder tumors using morphometry and then compare these with results of histologic grading of the same tumors by different pathologists. Nuclear sizes of cells obtained from superficial and deep cell layers of each carcinoma and from giant cells were measured in 27 cases in which histologic tumor grading by different pathologists was unequivocal. In cells from all three areas, nuclear area increased with higher tumor grade. However, tumors of grades I and II showed significant differences in the size only of the large cells. It is concluded that morphometry is a valuable tool in the objective grading of bladder tumors, with the exception of carcinoma in situ lining the bladder lumen.